Separately, it's worth addressing the fact that developer conversations do take place on the fediverse. It happens organically all the time, because like I said above, all activitypub developers are on the fediverse.
The problem here is that the de facto implementation is Mastodon, and the conversations taking place on Mastodon are by design ephemeral.
Arguments can be made that Mastodon does keep a copy of all of the conversations, and one need only look for them, but they're buried in such a way as to be essentially lost to history forever. You've probably tried looking for something you or someone else said, and started scrolling a profile feed endlessly looking for it... don't lie, we've all done it.
This is where we can throw technology at the problem... by building really good search, we can mitigate some of these losses. However this relies on people to actually use the search functionality, which is hard to guarantee 
Another solution is proper categorization of content... and this is where you'll say I have a bias. I certainly do! I'm a purveyor of forum software... the age old way of communicating online where stuff gets categorized and organized topically. To add this layer of human organization on top gets us that much closer to ensuring that the discussions we have and the discoveries we make are not simply lost to time, but preserved for future developers to re-discover and re-consume.
cc @fediversereport@mastodon.social @julian@activitypub.space